A burial vault is a container to hold a casket during burial and to protect and seal the casket from the environment. Historically, burial vaults were constructed of thick concrete walls with a concrete slab top. Westenhaver disclosed a plastic casket and burial vault in U.S. Pat. No. 2,508,319. Since that date various constructions of plastic burial vaults have been disclosed in prior art patents, including U.S. Pat. Nos. 2,806,278; 2,916,797; 3,208,186; 3,295,179; 3,581,452; 3,983,206; 4,154,031; 4,253,220; 4,288,952; 4,727,632; and 5,121,529. Typically, the problems that have been addressed in these patents concern the strength and the sealing of the vault. For example, U.S. Pat. No. 4,154,031, entitled "VAULT", teaches a construction having integral ribs or imbedded rods to enhance the rigidity of the vault and its load supporting strength during usage, while U.S. Pat. No. 3,983,206, entitled "SEALANT SYSTEM FOR BURIAL VAULT AND METHOD OF APPLICATION", discusses the importance of a good seal about the periphery of a burial vault.
U.S. Pat. No. 4,253,220, entitled "BURIAL VAULTS", is most similar in shape to the present invention. It discloses a burial vault including a base and a cover moulded from plastic resinous material. The base and the cover have reinforcing ribs formed integrally on the inner surfaces of the side and end walls. Further reinforcing ribs are formed on the bottom of the base and on the top inner surface of the cover. The outer surfaces of the cover and the base have geometrically shaped recesses to receive decorative panels. The cover and the base are sealed with tongue and groove sealing joints about their respective rims where they join.
It is an object of the present invention to provide an improved construction of a burial vault which enables the vault to be moulded in one operation, which simplifies the manufacture of the sealing joint and which provides a novel structure to provide strength and rigidity to the vault.